Nowadays, biopolymers such as antibody, peptide aptamer and nucleic acid have received attracted attention as next-generation drugs. The biopolymer should be handled differently from conventional drugs comprising a low molecular weight compound as active ingredient in various points such as quality control in manufacturing processes, storage of pharmaceutical preparations, and administration methods.
In general, amounts of the active ingredients to be delivered to target sites affects to response rate, when a pharmaceutical preparation is administered, depending on both of the disease to be treated and properties of the drug. For example, it is known that the problem that antibody produced depending on a dosage form at the time of administration reduced the efficacy of the administrated drug (therapeutic effects), when the drug comprising the biopolymer as active ingredient is administered.
Therefore, a variety of drug delivery systems (DDS: drug delivery system) have been developed actively as methods for delivering the pharmaceutical preparation to the target site properly. As the carrier for DDS, for example, there are mentioned such as liposome, plastic beads and the like. As the pharmaceutical preparation using such a carrier used for DDS, for example, there are reported those composed of a liposome, to which a ligand specifically binds to a localized molecule in the target site (see patent documents 1 and 2); the liposome or synthetic polymer beads, on which N-acetyl glucosamine or other sugars are exposed (see patent documents 3 and 4), micelles to which antibodies are bound (see patent document 5), and the like.
Also, the carrier utilizing dendrimer having micelle structure is developed (see patent documents 6, 7 and 8). The term, Dendrimer, is a generic word showing dendritic polymer compound has regularly branched structure, of which origin is Greek term “dendra” (trees). Several dendrimer molecules assemble to be spherical form having a nanometer scale space in its inside. Then, since the molecules are incorporated so as to show various functional groups in the space, it has higher flexibility of design. Therefore, currently, various new dendrimers are been developed actively in the field of nanotechnology.
Until now, in order to prevent and/or medicate a disease caused by viral or bacterial infections, the carrier utilizing dendrimer has been developed (See, patent Document 9).
On the other hand, it is known that the dendrimer having silole group shows AIE (aggregation-induced emission) usually to generate fluorescence emission when they form micelles, because it is equivalent the aggregate formation. Here, the term, AIE, which is defined as a phenomenon that the mutually aggregated light-emitting compounds gives high-efficient light emission after they are irradiated by the light with certain wavelength (See, non-patent document 1).